1
CHAPTER
2The Biological Basis of Behavior
Links to Learning Objectives
ENDURING ISSUES IN THE BIOLOGICAL
BASIS OF BEHAVIOR
NEURONS: THE MESSENGERS
Types of neurons
Transmitting information
Synapse and neurotransmitters
Neural plasticity and neurogenesis
THE CENTRAL NERVOUS SYSTEM
Parts of the brain and their functions
Tools for studying the brain
Spinal cord
THE PERIPHERAL NERVOUS
SYSTEM
Somatic and autonomic nervous systems
Sympathetic and parasympathetic nervous systems
THE ENDOCRINE SYSTEM
Endocrine glands and their hormones
GENES, EVOLUTION, AND BEHAVIOR
Heredity-environment
Passing traits from generation to generation
Methods for studying genes and behavior
Key ethical issues
Natural selection
Enduring Issues
To what extent
is behavior caused by
internal processes,
as opposed to
environmental
factors?Diversity-
Universality
Stability-Change
Mind-Body
Nature-Nurture
Person-Situation
2
Enduring Issues
To what extent does
heredity affect behavior?
Diversity-
Universality
Stability-Change
Mind-Body
Nature-Nurture
Person-Situation
Enduring Issues
Does the nervous
system change due to
experience?
Diversity-
Universality
Stability-Change
Mind-Body
Nature-Nurture
Person-Situation
Enduring Issues
Are there differences
between men and women in the
way that the brain works?
Diversity-
Universality
Stability-Change
Mind-Body
Nature-Nurture
Person-Situation
3
Enduring Issues
What is the connection
between what we experience
and our biological
processes?
Diversity-
Universality
Stability-Change
Mind-Body
Nature-Nurture
Person-Situation
Psychobiology and Neuroscience
Psychobiology:
Focuses on biological
bases of behavior and
mental processes
Neuroscience:
The study of the brain
and the nervous system
Neurons: The Messengers
4
Complex
network of
cells that
carry
information to
and from all
parts of the
body
e r v o u ss y s t e m
The Neuron
Terminal buttons
Axon
Cell body (soma)
Myelin
LEARNING OBJECTIVE: Describe a typical neuron. Distinguish between afferent,
efferent, and association neurons.
Dendrites
Three Types of Neurons
Afferent
(sensory) neurons
Efferent
(motor) neurons
Association
neurons
(interneurons)
5
Mirror Neurons“Found in the brains of humans and other primates, mirror neurons appear to
play a key role in how a primate’s brain is wired to mimic the sensations and
feelings experienced by other related animals and, thus, to identify and
empathize with them (Ramachandran, 2005; Rizzolatti et al., 2008).”
– Pages 42-43 (Morris & Maisto)
The Neural Impulse
LEARNING OBJECTIVE: Describe how neurons transmit information, including the
concepts of resting potential, polarization, action potential, graded potential,
threshold of excitation, and the all-or-none law.
All-or-None Law
The neuron either
fires completely
or it does not fire
at all.
6
The Synapse
LEARNING OBJECTIVE: Describe the parts of the synapse and the role of
neurotransmitters in the synapse.
Terminal button
Neurotransmitters
Applying Psychology
• Caffeine
• Cocaine
• Antidepressants
• Botulism
• Black widow spider
• Antipsychotics
7
Effects of Cocaine
Neural Plasticity and Neurogenesis
Neural plasticity:
Experience can change
the brain structurally
and chemically.
• Rosenzweig (1984)
Neurogenesis:
Adult brains can
produce new
brain cells.
LEARNING OBJECTIVE: Explain “neural plasticity” and “neurogenesis.”
Source: From “Brain changes in response to experience” by M. R. Rosenzweig, E. L. Bennett, and M. C. Diamond. Copyright © 1972, Scientific American, Inc.
The Central Nervous System
8
The Organization of the Nervous System
PERIPHERAL
Autonomic Somatic
Parasympathetic Sympathetic
Brain
CENTRAL
Spinal Cord
Central Nervous System
Brain
CENTRAL
Spinal Cord
The Brain
The human brain is the
product of millions of
years of evolution in
three stages:
• Central core
• Cerebral cortex
• Limbic system
LEARNING OBJECTIVE: Identify the parts of the brain and their function. Explain what
is meant by “hemispheric specialization” and the functional differences between the
two cerebral hemispheres.
9
The Central Core
Hindbrain
Midbrain
Thalamus
Hypothalamus
Reticular formation
Structures in the Hindbrain
Outer surface
of the two
cerebral
hemispheres
that regulates
most complex
behavior
e re b ra lc o r t e x
10
Four Lobes of the Cerebral Cortex
Both the left and right hemispheres can be
roughly divided into four sections.
The Limbic System
Limbic system: Ring of structures
that plays
a role in learning
and emotional
behavior
11
Hemispheric Specialization
The Split-Brain Experiment
The corpus callosum is sometimes severed to reduce seizures.
• Left visual field right hemisphere
• Right visual field left hemisphere
Broca’s Area & Wernicke’s Area
12
Handedness“A common misconception is that hemispheric specialization is related to
handedness…many people mistakenly believe that in left-handed people the
right hemisphere governs language, analytic, and sequential tasks, whereas the
left hemisphere dominates in visual, spatial, and nonverbal tasks. The fact is
that speech is most often localized in the left hemisphere for both right- and
left-handed people.”
– Page 59 (Morris & Maisto)
• Microelectrode techniques
• Macroelectrode techniques
– EEG
• Structural imaging
– CAT or CT scanning
– MRI
• Functional imaging
– EEG imaging
– MEG, MSI
– PET scanning
– fMRI
Tools for Studying the Brain
LEARNING OBJECTIVE: Discuss how microelectrode techniques, macroelectrode
techniques, structural imaging, and functional imaging provide information about the brain.
The Spinal Cord
LEARNING OBJECTIVE: Explain how the spinal cord works.
Spinal cord:
• Complex cable of neurons
that runs down the spine,
connecting the brain to most of
the rest of the body
• Functions as a “communication
superhighway”
13
The Spinal Cord and Reflex Action
Motor neurons
Sensory neurons
Interneurons
The Peripheral Nervous System
Peripheral Nervous System
Parasympathetic
PERIPHERAL
Autonomic
Sympathetic
Somatic
14
Peripheral Nervous System
Peripheral nervous system
(PNS): Links the brain and
spinal cord to the rest of
the body
• Afferent neurons
• Efferent neurons
LEARNING OBJECTIVE: Identify the peripheral nervous system and contrast the
functions of the somatic and autonomic nervous systems.
PERIPHERAL
Autonomic Somatic
Subsystems in the PNS
PERIPHERAL
Autonomic Somatic
LEARNING OBJECTIVE: Explain the differences between the sympathetic and the
parasympathetic nervous systems.
Parts of the Autonomic Nervous System
Parasympathetic
PERIPHERAL
Autonomic
Sympathetic
Somatic
15
Autonomic NS: Sympathetic
“Fight or flight”
Source: Adapted from General Biology, revised edition, 1st edition by Willis Johnson, Richard A. Laubengayer, and Louis E. Delanney,
Copyright © 1961. Reprinted with permission of Brooks/Cole, an imprint of the Wadsworth Group, a division of Thomson Learning.
Autonomic NS: Parasympathetic
Source: Adapted from General Biology, revised edition, 1st edition by Willis Johnson, Richard A. Laubengayer, and Louis E. Delanney,
Copyright © 1961. Reprinted with permission of Brooks/Cole, an imprint of the Wadsworth Group, a division of Thomson Learning.
“Rest and digest”
The Endocrine System
16
The Endocrine System
LEARNING OBJECTIVE: Describe the endocrine glands and the way their hormones
affect behavior.
Genes, Evolution, and Behavior
Behavior
Genetics
Genes, Evolution, and Behavior
Two different but related fields contribute to
the understanding of the influence of heredity
on behavior:
LEARNING OBJECTIVE: Distinguish between genetics, behavior genetics, and
evolutionary psychology.
Evolutionary
Psychology
17
LEARNING OBJECTIVE: Differentiate between genes, chromosomes, DNA, and the human genome. Describe what is meant by dominant and recessive genes, polygenic inheritance, and genotype vs. phenotype.
Genetics
B = dominant
gene
Transmission of Eye Color
b = recessive
gene
Behavior Genetics
Animal behavior genetics
• Strain studies
• Selection studies
LEARNING OBJECTIVE: Compare and contrast
strain studies, selection studies, family studies,
twin studies, and adoption studies as sources
of information about the effects of heredity.
18
Behavior Genetics
Human behavior genetics
•Family studies
•Twin studies
– identical twins
– fraternal twins
•Adoption studies
Average Risk of Schizophrenia Among Biological Relatives of People with Schizophrenia
Source: From The Origins of Madness by Irving I. Gottesman, Henry Holt and Company, LLC, 1991, p. 96.
Social Implications
New challenges have arisen as a result of our better understanding of genes.
LEARNING OBJECTIVE: Identify the key ethical issues that arise as society gains more
control over genetics.
• Modern prenatal screening
can detect genetic defects;
do parents have the right
to abort because of this?
• Over-simplified reporting
of genetic technologies in
mass media can lead to
misinterpretation of
complex research findings.
19
Evolutionary Psychology
Evolutionary psychology examines adaptive value of behaviors from an evolutionary perspective.
• Darwin’s natural selection
LEARNING OBJECTIVE: Describe how
evolutionary psychologists view the
influence of natural selection on human
social behavior.
Charles Darwin
Lecture Activities
If the neural
impulse fires
with same
“strength”
every time it
fires, how can
you tell the
difference among
different stimulus
intensities?
20
?!Peer Instruction
I’ve often heard that people only use 10% of their brain. However, even a relatively simple task like playing a piano or even just tapping along to music requires many parts of the brain to be active — well over 10%. In fact, I’ll bet that you have a tough time figuring out which part of the brain would most likely NOT be activated by playing the piano?
A. Pons
B. Pituitary gland
C. Hippocampus
D. Thalamus
On the next slide, you
will read about three
psychological scenarios.
In small groups, discuss
which brain areas/systems
are probably being
activated in these
scenarios.
Shandra is a painter. She is standing by her easel. The window is open and she can smell the jasmine flowers in her yard. She is painting with her right hand. She can hear her children playing in the background.
Melanie is a police officer. She is preparing for her rank-advancement exam. It’s late at night. She is reading through some material and viewing pictures related to brutal murder cases. She is drinking coffee and eating a sandwich.
James is a football player. He is the quarterback in a tough game and the home crowd is yelling and screaming. It’s the fourth quarter and James is tired and sweating as he goes up to hike the ball. After hiking the ball, he and his teammates execute some very complicated running and passing routes to execute a play.
21
Split-Brain Experiment
Sperry and Gazzaniga devised a creative experiment to test hemispheric functioning. In this experiment, visual stimuli were shown to either the LEFT or RIGHT visual fields of split-brain patients.
On the next slide, you will see a red “X.” Stare at the X until you are asked to provide a verbal response.
Trial #1(Click anywhere to begin)
X
CONTINUETRY AGAIN
What did you see?
22
Trial #2(Click anywhere to begin)
X
CONTINUETRY AGAIN
What did you see?
I saw nothing.How do you think a split-brained
patient would respond when asked to
identify an object flashed to the LEFT
VISUAL FIELD?
It’s a ball!
Given what you now know about how the brain
processes information from the two visual fields,
how do you think a split-brained patient would
respond when asked to identify an object flashed
to the RIGHT VISUAL FIELD?
23
In small groups, discuss how the sympathetic NS functions help out in a “fight or flight” situation. What are the implications when the sympathetic NS remains active for extended time periods?
Source: Adapted from General Biology, revised edition, 1st edition by Willis Johnson, Richard
A. Laubengayer, and Louis E. Delanney, Copyright © 1961. Reprinted with permission of
Brooks/Cole, an imprint of the Wadsworth Group, a division of Thomson Learning.
Acknowledgments
Slide # Image Description Image Source
text template upside down blue sky & grass©iStockphoto.com/Konrad Lew
chapter template
brain scan ©istockphoto.com/Ray Roper
3 man's head ©istockphoto.com/iofoto
3 heights ©istockphoto.com/Adventure Photo
4 chromosomes ©istockphoto.com/Alex Mit
5 neuron ©istockphoto.com/ktsimage
6 young couple ©istockphoto.com/ATMarshallphotography
7 someone whose brain is being studied in a lab ©istockphoto.com/annedde
8 boy jumping ©istockphoto.com/Nicolesy Photography | Nicole S. Young
8 icon: helmet ©istockphoto.com/Li Shen Jun
8 neuron ©istockphoto.com/ktsimage
10 wires ©istockphoto.com/Take A Pix Media
11 neuron ©istockphoto.com/ktsimage
12 afferent - hand ©istockphoto.com/Joshua Blake
12 efferent - motor ©istockphoto.com/Rob Belknap
12 association - chain ©istockphoto.com/Jessica Jones Photography Ltd
12 shoulder / candle From Ciccarelli, Psychology, 2/e p. 59
13 Open Your Book - text book cover Shutterstock
13 Open Your Book - textbook background From Ciccarelli, Psychology, 1/e pp. 213-214
13 Open Your Book - open textbook From Ciccarelli, Psychology, 1/e pp. 114-115
14 neuron illustration From Ciccarelli, Psychology, 2/e p. 52
15 diagram - neuron firing From Morris/Maisto, 9/e p. 46
15 icon: wanted sign Charlie Levin, adapting wooden board image from ©istockphoto.com/andynwt
16 neuron ©istockphoto.com/ktsimage
16 synaptic vesicle illustration From Ciccarelli, Psychology, 2/e p. 54
24
16 lock icon ©istockphoto.com/KK-inc
16 key icon ©istockphoto.com/KK-inc
17 Table: Major Neurotransmitters and Their Effects From Morris/Maisto, 9/e p. 47
18 black widow spider ©istockphoto.com/[Mark Kostich] International Wildlife Photographer
18 scrap of paper ©istockphoto.com/Trevor Hunt
19 effects of cocaine illustration From Ciccarelli, Psychology, 2/e p. 57
20 rosenzweig illustrations (2) From Morris/Maisto, 9/e p. 49
22 heart icon ©istockphoto.com/twentyfourworks
22 brain & spine ©istockphoto.com/Mads Abildgaard
23 brain & spine ©istockphoto.com/Mads Abildgaard
24 brain ©istockphoto.com/Stephen Kirklys
24 icon: peer instruction Charlie Levin
25 head with brain illustration From Ciccarelli, Psychology, 2/e p. 68
26 head with brain illustration From Ciccarelli, Psychology, 2/e p. 68 (B&W closeup of previous slide image)
26 man yawning ©istockphoto.com/szefei
26 woman checking heart rate ©istockphoto.com/digital planet design
26 female gymnast ©istockphoto.com/Jiang DaoHua
27 brain ©istockphoto.com/Stephen Kirklys
28 two profiles with lobes illustration From Ciccarelli, Psychology, 2/e p. 74
29 profile with lobes illustration From Ciccarelli, Psychology, 2/e p. 74
29 icon: helmet ©istockphoto.com/Li Shen Jun
29 thinking ©istockphoto.com/Bart Coenders
29 yoga ©istockphoto.com/Carlos Alvarez
29 eye ©istockphoto.com/Bart Coenders
29 ear ©istockphoto.com/Bart Coenders
30 limbic system illustration From Morris/Maisto, 9/e p. 56
31 hemispheric specialization illustration From Morris/Maisto, 9/e p. 57
32 split-brain experiment illustrations From Morris/Maisto, 9/e p. 58
32 Get in the Game helmet ©istockphoto.com/Li Shen Jun
33 Broca's area and Wernicke's area illustration From Morris/Maisto, 9/e p. 59
34 Open Your Book - Morris book cover Shutterstock
34 Open Your Book - textbook background From Ciccarelli, Psychology, 1/e pp. 213-214
34 Open Your Book - open textbook From Ciccarelli, Psychology, 1/e pp. 114-115
35 someone whose brain is being studied in a lab ©istockphoto.com/annedde
36 illustration brain & spinal cord From Morris/Maisto, 9/e p. 62
37 ilustration shoulder & candle From Ciccarelli, Psychology, 2/e p. 59
39 heart icon ©istockphoto.com/twentyfourworks
39 man running ©istockphoto.com/Pete Saloutos
39 heartbeat Derek Borman
40 illustration of body w/ nervous system From Ciccarelli, Psychology, 2/e p. 62
40 soccer girls ©istockphoto.com/Alberto Pomares Photography
41 heart icon ©istockphoto.com/twentyfourworks
41 man running ©istockphoto.com/Pete Saloutos
42 heart icon ©istockphoto.com/twentyfourworks
42 man running ©istockphoto.com/Pete Saloutos
43 man running ©istockphoto.com/Pete Saloutos
43 sympathetic & parasympathetic illustration From Morris/Maisto, 9/e p. 64
43 icon: wanted sign Charlie Levin, adapting wooden board image from ©istockphoto.com/andynwt
44 sympathetic & parasympathetic illustration From Morris/Maisto, 9/e p. 64
44 napping woman ©istockphoto.com/Daniel Bendjy
46 man and woman endocrine system illustration From Ciccarelli, Psychology, 2/e p. 80
49 genetics illustration From Morris/Maisto, 9/e p. 69
50 eye color diagram From Morris/Maisto, 9/e p. 71
51 lab mice ©istockphoto.com/Floris Slooff
52 twins ©istockphoto.com/Chris Johnson
53 schizophrenia table From Morris/Maisto, 9/e p. 73
54 pregnancy exam ©istockphoto.com/Tamara Murray
54 laptop with breaking news ©istockphoto.com/Entienou
55 Darwin ©istockphoto.com/Steven Wynn
57 Wanted: Contemplation wanted sign Charlie Levin, adapting wooden board image from ©istockphoto.com/andynwt
57 Wanted: Contemplation cactus ©istockphoto.com/Lee Daniels
57 Wanted: Contemplation wooden board ©istockphoto.com/andynwt
57 man covering his ears ©istockphoto.com/Cat London Photography
57 guitarist ©istockphoto.com/deliormanli
58 Peer Instruction people icon Charlie Levin
58 Peer Instruction chalkboard ©istockphoto.com/Studio Araminta
59 Get in the Game helmet ©istockphoto.com/Li Shen Jun
59 Get in the Game football field ©istockphoto.com/Jamie Otterstetter
59 painter ©istockphoto.com/VikramRaghuvanshi
60 painter ©istockphoto.com/VikramRaghuvanshi
60 female police officer ©istockphoto.com/Katrina Brown
60 football player ©istockphoto.com/George Peters Design And Illustration
60 Get in the Game helmet ©istockphoto.com/Li Shen Jun
60 Get in the Game football field ©istockphoto.com/Jamie Otterstetter
61 Get in the Game helmet ©istockphoto.com/Li Shen Jun
61 Get in the Game football field ©istockphoto.com/Jamie Otterstetter
63 baseball ©istockphoto.com/Dan Thornberg
65 hammer ©istockphoto.com/Fuat Kose
66 split brain illustrations From Ciccarelli, Psychology, 1/e p. 71
67 Wanted: Contemplation wanted sign Charlie Levin, adapting wooden board image from ©istockphoto.com/andynwt
25
67 Wanted: Contemplation cactus ©istockphoto.com/Lee Daniels
67 Wanted: Contemplation wooden board ©istockphoto.com/andynwt
67 men fighting ©istockphoto.com/yulkapopkova
67 sympathetic & parasympathetic illustration From Morris/Maisto, 9/e p. 64
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